Planar format sensors have generally been described in the literature and are considered advantageous over three-dimensional sensors under many circumstances. The planar format typically comprises relatively thin layers of materials which are applied to a substrate base using thick-film or thin-film techniques, including, for example, silk-screen printing. Planar sensors are typically smaller than three-dimensional sensors and therefor the sensing instrument itself may be scaled down. Additionally the planar sensor is easily and inexpensively manufactured and simple to operate.
In preparing planar format sensors, performance issues must be addressed and remedied before commercializing the sensor. Problems associated with preparing a commercially acceptable bicarbonate sensor include, for example, inadequate lifetime of the sensor, slow response time of the sensor, and extended time frame required before the sensor reaches a stable potential upon the sensors first usage.
Planar bicarbonate sensors that offer an improved response with respect to the at least one of the above-enumerated problems are needed.